Lathe



L. A. CARTER May 24, 193s.

LATHE 2 Sheets-Sheet l Filed Aug. 26 1935 /N vsn/rok.' A

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May 24, 1938. L. A. CARTER 2,118,439

' LATHE Filed Aug. 26, 1935 2 Sheets-Sheet 2 gai 'A 30 /m/E/vroe:

Patented May 24, 1938 UNI-TED s'rn'rss ESAS? y LATCHE Lionel A.. Carter, Webster Groves, Mo.

Application August 261,

13 Glaims.

This invention relates to' lathes of the type wherein the carriage feed employed for screw cutting includes a change speed mechanism for driving the feed screw at different selected' speeds to cut screws lof various leads. lThe inventio-n has for its principal object to provide a plurality of additional' lead changes for each lead change obtained by the change speed leadv screw driving mechanism. Othery objects are' the simplicity and cheapness of construction and compactness of design. The invention consists in providing drive means for thel auxiliary slide, whereby the tool' may be moved at a faster or slower rate of travel than the carriage. The invention also conf' sist-s in theconstruction and' combinations and arrangements of parts hereinafter describedV and claimed.

In the accompanying drawings, which form part of this specification and wherein like symbols refer to' like parts wherever they occur,

Fig. 1 is a fragmentary front elevation. of a screw cutting lathe embodying my invention;Y

Fig. 2 is an enlarged fragmentary front ele'- Vation ofthe lathe carriage an-d the part-'s adjacent thereto;

Fig. 3 is a vertical section on thev line 3 3 in Fig.42`;

Fig. 4 is a horizontal transverse section on. the line 4--4 in Fig. 2;

" Fig. 5 is a vertical longitudinal section on the line 5-5 in Fig. 3;

Fig. 6 is a horizontal section through the carriage apron on the line ESV-6 in Fig. 2; and

Fig. 'l is a vertical cross section on the line 'l-l in Fig. 5.

Referring to the accompanying drawings', my invention is shown embodied in the carriage of'A a screw-cutting lathe comprising a bed I, a carriage 2 mounted on said bed for sliding movement longitudinally thereof between a head'stock 3 and a tailstock il, a lead screw 5'fjor sliding said carriage along said bed, and a housing 6' located beneathlsaid head stock and contianing a suitable uuick change Vmechanism (not shown) for driving said ylead screw at different selected speeds. The carriage 2 has the usual cross slide 8 mounted thereon, whose operating mechanism includes an operating handle Sl `locatedr on the apron portion I!) of said carriage. The cross `slide 8 has an auxiliary sli-de I l mountedthereon for movement in the direction in which the carriage moves; and said auxiliary slide is provided with the usual post- 'iZ for supporting a: suitable thread-cutting tool. The auxiliary slide ll is slid -*al'ong-the cross slide 8 by means of a feed screw 1935, Serial No. 371,312

(01;V S21-5l I3" mounted in said auxiliary slide and provided at its outer end with an operating handle i3d.

The carriage 2 is connected to and disconnected from the lead screw 5 by a feed nut ll comprising upper and lower half-nuts 'that are mounted 5 toI slide vertically in apron lis of said carriage. The feed nut lll is clamped on. and released from the lead screw by a. pair of curved links l5 that are connected at their adjacent ends to alrotary disk i6 and at their. remote ends to the respective l0 half-nuts or sections of said feed nut. The disk i6 is mounted on a rock shaft il journaled in the carriage apron il) andV provided outside of said apron with a` suitable operating handle i8. The carriage 2 is manually actuated by means l5 of a hand wheel i9 fixed to the outer end of a horizontal shaft 20 that isjournaled in. the apron Iii` and has a pinion 2l fixed to its inner end. that intermeslies with a gear 22 fixed toy a shaft 23 that is journaled in said apron and is provided` 20 with a pinion 24 that cooperates with a rack 25 xed to and disposed longitudinally of the lathe bed.

By the arrangement described', the` quick change mechanism varies the rate of carriage 25 feed consequently the rate of tool feed to cutl screws of various leads. In accordance with the present invention, the above lathe is provided with meansfor providing a plurality o-f additional lead changes for each speed. change of the quick 30 change mechanism. As shown in the drawings,4 this additional lead. changing means comprises horizontal shaft 26 journaled in the carriage apron it and provided at. its inner end with a pinion 2l, whichY cooperates with. and is driven. 35 bythe longitudinal rack 25 on the lathe bed i, and at itsouter end with a loose gear 'adapted to be clutched to said shaft by means of a suitable clutch sleeve 29 provided at its outer end with a. knurled operating knob 3G. The gear 23 40 is in continuous. mesh with a gear 3l which is in continuous mesh with. a smaller gear 32. The .gears 3! and 32 are mounted on shafts supported in a quadrant in the. form of .a triangular plate 33 that is rotatably mounted on the` drive shaft 45 26, whereby the vquadrant may be rotated on its pivotal axis to bring the gear 3lA or the gear 32, into mesh with .a gear 34, fixed to a horioontal shaft 35 journaled in a bearing. 3E. provided therefor on top of the carriage 2; The shaft' 35 is 50 disposed crosswise of the carriage and extends beneath` and is operatively connected to the screw i3' for actuating the auxiliary slidev il.. The gear supporting quadrant plate 3,'3 ispro.- vided with a handle 53a for rotating said' plate 65 to bring either one of the two gears 3l, 32 thereon into mesh with the gear 34 on the outer end of the feed screw operating shaft 35. Said plate is locked in either one of its positions of adjustment by means of a stud Illa that is fixed to the apron I0, extends through an arcuate slot 33h provided therefor in said plate and is provided at its outer end with a nut IGZ)` adapted to bear against the outer face of said plate.

The feed screw I3 has a loose fit in an axial bore provided therefor in a lateral extension 8a of the cross slide 8 and is rotated from the gear-driven shaft 35 by means of a worm 38 that rotates with but is slidable axially of said shaft and cooperates with a worm gear 3T, through which said screw is threaded. The worm gear 31 is mounted in a downwardly opening recess provided therefor in the lateral extension 8a of the cross slide 8; and the worm 35 is formed on a sleeve 38 that has a key 39 fitting a spline 4!! provided therefor in the shaft 35, whereby said shaft is movable with the cross slide 8 axially of the worm without disturbing the driving connection therebetween. The inner end of the feed screw I2 is mounted for rotary, but non-axial movement, in taper roller bearings 4I enclosed within a housing 42 that is fixed to the underside of the auxiliary slide ll. The feed screw is splined, as at 13b, and a sleeve 43 has a feather key 44 fitting within .said spline. The sleeve 43 is mounted in the outer end portion of the lateral extension 8a of the cross slide in abutting relation to the outer end face of the worm gear 3l, which portion is made in the form of a removable section 8b of said extension; and said sleeve is held against axial movement in said extension by a flange 43a on the inner end thereof and a ring nut 45 threaded on the outer end thereof in abutting relation to said extension. A set screw 46 is threaded into the section 8b of the cross slide extension 8a in abutting relation to the sleeve 43. When the set screw is released, manual adjustment of the slide Il may be afforded by turning the handle i3d on the feed screw I3. When said set screw is tightened against the sleeve 43, said sleeve is held against rotation and the slide Il is actuated by travel of the worm nut 31 along said screw.

By the arrangement described, the lead obtained by any one of the speed changes available through the quick change mechanism may be slightly increased or decreased by means of the driving connection between the carriage 2 and the auxiliary slide feed screw Il. When the carriage moves along the bed, with the clutch 29 engaged andthe set screw 46 tightened against the sleeve 43 splined and threaded on the auxiliary slide feed screw Il, the pinion 2l' is rotated by the rack 25, thereby actuating the driving connection between said pinion and the worm nut 3l on the auxiliary slide feed screw i l and thus causing said nut to travel along said screwr that which would be produced if the tool were moving at the same speed as the carriage. When the drive is transmitted from the gear 28 to the gear 34 through the gear 3l and the changespeed gear 32, the travel of the tool-supporting slide is slower than the carriage, thereby producing a screw of less lead than that which would be produced if the tool were moving at the same rate of speed as the carriage.

Obviously, the hereinbefore described construction admits of a considerable amount of modification without departing from the invention. Therefore, I do not wish to be limited to the precise construction shown and described.

What I claim is:

l. The combination of a bed, a carriage slidable on said bed, a lead screw feed mechanism for said carriage, feed mechanism for said carriage including a rack on said bed, a member sustained by and movable relative to said carriage in the direction of the carriage feed, and means for feeding said member at a faster or slower rate of travel than said carriage, said means including a pinion journaled on said carriage for movement therewith and meshing with and driven by said rack.

2. The combination of a bed, a carriage slidable on said bed, feed mechanism for moving said carriage at a definite rate of feed, a member sustained by and movable relative to said carriage in the direction of the carriage feed, and toothed gearing mounted on and operated by the sliding movement of said carriage for feeding said member at a faster or slower rate of travel than said carriage, whereby the rate of carriage feed is modified by the different rates of feed of said member.

3. The combination of a bed, a carriage slidable on said bed, feed mechanism for moving said carriage at a definite rate of feed including means for changing the rate of carriage feed, a member sustained by and movable relative to said carriage in the direction of' the carriage feed, and toothed gearing mounted on and actuated by the movement of said carriage for causing relative movement of said carriage and said member, whereby the rate of carriage feed is modied by the different rates of feed of said member.

4. The combination of a bed, a carriage slidable on said bed, a change-speed feed mechanism for moving said carriage at a definite rate of feed, a tool supporting member sustained by and movable relative to said carriage in the direction of the carriage feed, and a changespeed toothed drive gear connection between said carriage and said member operated by the movement of said carriage for feeding said member at a different rate of travel from said carriage, whereby the rate of carriage feed is modified by the different rates of feed of said member.

5. The combination of a bed, a carriage slidable on said bed, a feed mechanism for said carriage, a. member sustained by and movable relative to said carriage in the direction of the carriage feed, and a driving connection between said carriage and. said member operated by the movement of said carriage for feeding said member at a different rate of travel from said carriage, said driving connection including toothed change speed gearing for changing the rate of travel of said member, and means for rendering said. driving toothed gearing inoperative by the movement of said carriage.

6. A lathe comprising a bed, a carriage slidable thereon, change speed feed mechanism for said carriage, a cross slide mounted on said carriage, an auxiliary slide mounted on said cross slide for movement in the direction of the carriage feed, a feed screw for said auxiliary slide, and a driving connection between said carriage ana-189v and said feed screw including a wheel journaled on said carriage and driven by the movement of said carriage for moving said auxiliary slide at a different rate of feed from said carriage feed.

'7. A lathe comprising a bed, a carriage slidable thereon, feed mechanism for said carriage, a cross slide mounted on said carriage, an auxiliary slide mounted on said cross slide for movement in the direction of the carriage feed, a feed screw operatively connected to said auxiliary slide, and a driving connection between said carriage and said feed screw including a nut threaded on said feed screw and mounted in said cross slide against axial movement, a worm gear on said nut, a shaft journaled on said cross slide parallel to the direction of movement thereon, a sleeve slidably splined on said shaft and having a worm thereon intermeshing with said worm gear, and means operated by the movement of said carriage for driving said shaft.

8. A lathe comprising a bed, a carriage slidable thereon, change speed feed mechanism for said carriage, a cross slide mounted on said carriage, an auxiliary slide mounted on said cross slide for movement in the direction of the carriage feed, a feed screw operatively connected to said auxiliary slide, and a driving connection between said carriage and said feed screw including a nut threaded on said feed screw and mounted in said cross slide against axial movement, a worm gear on said nut, a shaft journaled on said cross slide parallel to the direction of movement thereon, a sleeve slidably splined on said shaft and having a worm thereon intermeshing with said worm gear, and change speed gearing operated by the movement of said carriage for driving said shaft.

9. A lathe comprising a bed having a longitudinal rack, a carriage slidable thereon, change speed feed mechanism for said carriage, a cross slide mounted on said carriage, an auxiliary slide mounted on said cross slide for movement in the direction of the carriage feed, a feed screw for operating said auxiliary slide, and a driving connection between said c arriage and said feed screw including a nut threaded on said feed screw and mounted in said cross slide against axial movement, a worm gear on said nut, a shaft journaled on said cross slide parallel to the direction of movement thereon, a sleeve slidably splined on said shaft having a worm thereon intermeshing with said worm gear, and change speed mechanism operated by the movement of said carriage for driving said worm shaft, said mechanism comprising a drive shaft journaled on said carriage, a pin on said drive shaft cooperating with said rack, a gear on said drive shaft, a gear on said worm shaft, a plate mounted on said carriage for pivotal movement about the drive shaft axis, a gear journaled on said plate in continuous mesh with the gear on said drive shaft, and a gear journaled on said plate in continuous mesh with said last mentioned gear, the two last mentioned gears being adapted to be selectively meshed with the worm shaft gear by rocking the pivoted supporting plate for said two gears.

10. In a machine tool, the combinatin of a bed, a carriage slidable on said bed, a power driven feed screw for moving said carriage along said bed at a definite rate of travel, a member slidably sustained by said carriage, and means operated by the travel of said carriage along said bed for moving said member relative to said carriage in the direction of but at a different rate of travel from the carriage travel, whereby the definite rate of carriage travel is modified by the different rate of travel of said member, said means including a wheel journaled on said carriage in rolling contact with a stationary reaction portion provided therefor on said bed.

l1. In a machine tool, the combination of a bed, a rack on said bed, a carriage slidable on said bed, a power driven feed screw for moving said carriage along said bed at a definite rate of travel, a member slidably sustained by said carriage, and means operated by the travel of said carriage along said bed for moving said member relative to said carriage in the direction of but at a different rate of travel from the carriage travel, whereby the definite rate of carriage travel is modified by the different rate of travel of said member, said means including a pinion rotatably supported on and movable with said carriage and meshing with and driven by said rack.

12. In a machine tool, the combination of a bed, a carriage slidable on said bed, a power driven feed screw for moving said carriage along said bed at a definite rate of travel, a member slidably sustained by said carriage, and means operated by the travel of said carriage along said bed for moving said member relative to said carriage in the direction of but at a different rate of travel from the carriage travel, whereby the definite rate of carriage travel is modified by the different rate` of travel of said member, said means including a wheel journaled on and movable with said carriage and in rolling contact with a stationary surface.

13. In a machine tool, the combination of a bed, a carriage slidable on said bed, a power driven feed screw for moving said carriage along said bed at a definite rate of travel, a member slidably sustained by said carriage, and means' operated by the travel of said carriage along said bed for moving said member relative to said carriage in the direction of but at a different rate of travel from the carriage travel, whereby the definite rate of carriage travel is modified by the different rate of travel of said member.

LIONEL A. CARTER. 

